Mechanical airway valves are placed within an airway to prevent air from flowing in selected portions of a lung.
It would be attractive to have a valve with two or more sets of struts for forming a seal with a passageway. What is needed is two or more sets of struts with different expansion radii so that a single valve can seal multiple different sized passages or irregularly shaped passageways. It would be attractive to have a valve with two or more membranes that contact the passageway to form a seal. What is needed is two or more membranes that form a seal with a passageway such that if one membrane does not form a complete seal a second membrane seals the passageway to form a complete seal between the two or more membranes.